Endoscopes having shafts that include working channels are known in the art. However, prior art endoscope shafts suffer from various deficiencies when passing an instrument, such as a forceps, through the working channel of an endoscope shaft. Such problems are exacerbated when the endoscope shaft is flexible and/or bendable.
Problems in prior art endoscopes include the working channel running over the edge of a push-pull wire bushing, which creates a bump in the working channel. A bump in the working channel may block instruments that are passed through the working channel. When this occurs, it is possible to feel an obstacle inside the working channel, which is disadvantageous. Furthermore, if instruments move over the bump several times, the instruments may wear a hole inside the wall of the working channel. This may cause the wall of the working channel to leak and may cause the endoscope to cease to be operational.
In prior art endoscopes, there are usually two or four wires in the endoscope and therefore there is typically more than one bushing within the endoscope, as the bushing typically includes at least one wire. Thus, there are multiple points where the working channel runs over a wire bushing and where the wire bushing presses against the channel. Thus, there are multiple points where a bump may be created in the working channel that can block instruments in prior art endoscopes.
Another disadvantage of the prior art includes having a complicated distal tip assembly procedure that is due to the limited space inside the endoscope shaft.
Thus, it is desirable to provide an endoscope and endoscope shaft assembly that solves the above mentioned problems in the prior art. The pending application is set to overcome these aforementioned disadvantages.